Trainer mileage

dennisn

How is mileage determined on a trainer(not rollers)? Just because the tire is going around,
does that mean that you've effectively traveled whatever distance(on the road) that
your computer says you have??? Doesn't tire pressure against the roller(which can vary) have an effect on the, so called, distance that you traveled??? Can any of this be accurately measured on these high dollar trainers(or any one for that matter) that supposedly let you ride a simulation of some famous climb or route, along with a video??
Seems to me to be more hype than anything. Not denying the workout value, just questioning whether it has any relation to reality. Friend of mine keeps telling me how he rode this or that famous course or climb. I mean, he's in his basement. Not Switzerland.
Sorry if I'm being overly skeptical.

Alex_Simmons/RST

On a Computrainer for instance (which has a very good ergo controller), if set up right (e.g. bike + rider mass and it is properly calibrated), then riding a pre-programmed course can reasonably replicate the speeds, since it does simulate the gradients and resistance requirements quite well. Well enough in fact to be able to conduct multi rider races over the same course.

However for trainers that don't have such good ergo controllers, or no ergo controller, then distance on a trainer is meaningless.

IOW - for the most part with trainers (just like out on the road), one should focus on intensity and duration as being the most important fitness training factors for any given ride (aside from other non-fitness training factors that may also be important like skills/social/enjoyment/safety).

terongi

I don't know the science behind it all, but if it's anything to go by...

My times for riding up the real Alpe D'Huez and the Tacx virtual reality version are within 3-4 minutes of each other.

I know that there are all kinds of variables like road surface, wind, climate etc, but it seems not bad as a rough estimation.

Mark Alexander

I can't see how most of us can afford the top-of-the-range kit that Alex is referring to. When I do a turbo or roller session even a road session I think of it as time on the bike not how may miles. That said, it is nice to think that 200 and 250 miles this Jan and feb was supplemented by a good few turbo hours.

StanwaySteve62

Well I started this year on a tacx to get some fitmess back after a long lay off and would say that keeping a log makes sense.
If you do a 30 min a day routine for example, you can see by the mileage you acheive, any improvements you may be making so whilst not comparable to the road it still gives you a subjective guide

terongi

StanwaySteve62 wrote:

If you do a 30 min a day routine for example, you can see by the mileage you acheive, any improvements you may be making

That only works if you set the slope (brake resistance) exactly the same every time, which is a bit dull..

A far easier constant to work with is average power over a set time measured in watts. Don't get started on how objectively accurate the tacx power meter is, but if you calibrate the machine each time after a 3-5 min warm up, then you have a constant benchmark for yourself and you can vary the slope as much as you like.

Eg if you climb a "slope" for 30 minutes with the same effort as you pedal a "flat" for 30 minutes, you will record the same average power, but vastly different "distances".

Alex_Simmons/RST

Yesterday I jumped on one of our Computrainer lab models for a moderate turbo session. Here is the pic showing the SRM power data and Computrainer power data overlayed. This is after a good 10-minutes warm up and proper calibration of the CT:



Now sometimes you see a slight difference between them but more importantly there is no drift apart through the effort.

Bsandow

Sort of on the topic... Does anyone know the correlation from rollers to road? Does 1hr steady state on rollers = 1hr road ride?

Alex_Simmons/RST

Bsandow wrote:

Sort of on the topic... Does anyone know the correlation from rollers to road? Does 1hr steady state on rollers = 1hr road ride?

training stress / workload per ride is a function of intensity, variability and duration.

if these 3 elements are the same, then yes it would correlate. Otherwise, no.